I have a stereo music signal corrupted by strong sinusoidal noise that varies over time. Here is the spectrogram of Left channel I plotted with Matlab. As you can see there are 3 or 4 strong harmonics with frequency that varies over time.
As a first try I computed the difference of left and right channels and it seems most of the harmonic noise disappears, so my guess is the noise in left and right are almost identical. Here is the difference spectrogram to prove this.
Which technique could I use now to filter away all the interfering harmonics while preserving the original music spectrum as well as possible?
- Notch filters?
- Tracking the frequencies over time and adding a sinusoid with reversed phase?
How do I estimate and use the phase information? I think phase is important to have good denoising, but would not know how to proceed.
Thanks a lot! :)